From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Investigation and proposed modifications for earthing the battery positive terminal.
| Identifier | ExFiles\Box 164\4\ img274 | |
| Date | 28th October 1936 | |
| Lr{Mr Ellor}/Wst.) By/RD.) from E.{Mr Elliott - Chief Engineer} e.{Mr Elliott - Chief Engineer} Sg.{Arthur F. Sidgreaves - MD} Ms. By.{R.W. Bailey - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} Run 6021. E.2/HP.28.10.36. Earthing of Battery Positive. With further reference to E.4/HP.8.10.36, this matter has now been more fully investigated, and we find that such a changeover would require alterations to all of the major bakelite mouldings used on the electrical system. There are also disadvantages in respect to the increased run of main cable required on the chassis frame to reach the other side of the battery. It has, therefore, been agreed that provided we can retain the advantage of the reversed polarity on the ignition system the main changeover is not worth while. The aforementioned change on the ignition carried out individually requires the high tension now being connected to the negative end of the primary winding, and the connections on the primary winding being reversed to obtain the correct polarity relative to the secondary winding. BY/RD has thoroughly investigated all the points that would be involved and finds that the scheme is quite practical. A modification to one moulding on the coil unit would be required to suit the different markings necessary. We, therefore, propose to go ahead with the battery earthed on the negative side, as at present, but with the ignition only changed round, to give us the reduction of operational voltage at the sparking plug points, with the improved consistency of operation. Coils will be instructed with this modification and put on experimental cars, with a view to standardisation. The same advantages of operation also apply to the aero ignition, for which a similar policy will be carried out, except that the aero ignition being still in the experimental stage, we shall merely proceed to change over all the units undergoing development. E.{Mr Elliott - Chief Engineer} | ||